Widely touted abstract on ivermectin and COVID-19 retracted

The authors of a controversial meeting abstract linking ivermectin to lower mortality from Covid-19 have retracted the study, saying that the work has been widely “misinterpreted” and might be leading to patient harm. 

The abstract, “Treatment with Ivermectin Is Associated with Decreased Mortality in COVID-19 Patients: Analysis of a National Federated Database,” was presented at the 2021 International Meeting on Emerging Diseases and Surveillance.

According to the researchers, from the University of Miami, Covid-19 patients who took ivermectin were about 70% less likely to die of the disease than those who took remdesivir. 

Ivermectin use was associated with decreased mortality in patients with COVID-19 compared to remdesivir. To our knowledge, this is the largest association study of patients with COVID-19, mortality and ivermectin. Further double-blinded placebo-controlled RCTs with large samples are required for definite conclusion. In the future, if more publications are published with the similar result to the current analyses, the certainty of evidence will increase.

Not surprisingly, the poster received a significant amount of attention on social media – both from ivermectin partisans and skeptics. At the time, the researchers tried to distance themselves from any firm conclusions about the work, stressing that they were reporting an association and not necessarily a causal effect. 

Evidently, they felt those protestations were insufficient – and indeed, the authors decided not to pursue publication of their work on the ground that the findings were too shaky. As the lead author, Ivakov Efimenko, tweeted: 

Here’s the notice

This article has been retracted at the request of the authors. The abstract was presented as a poster in the IMED last year. Our study was about the association of Ivermectin with reduction in mortality in COVID, a retrospective study with many limitations (which is innate in these types of studies). As in any retrospective study, we could not control for all the confounding variables, mainly severity of disease in patients treated with either ivermectin or remdesivir. Another important caveat is that it was conducted in July 2021, eight months ago, when we did not have all the clinical evidence we have right now about ivermectin in COVID-19. We were very clear in the abstract conclusions that our results are only showing an “association”, they are not definitive, and further randomized clinical trials must be done to prove the efficacy of Ivermectin. However, the study has been misinterpreted by a significant number of people in the scientific community and the general population, stating that based on our study, ivermectin is effective to reduce COVID-19 mortality. We are really concerned about this problem because the patients may start taking or demanding this medication from their physicians, which can potentially be harmful. We know that a retrospective study like ours cannot be used to change or guide clinical practice. Retrospective studies are only helpful to formulate hypothesis that can be utilized to design clinical trials. This misrepresentation of the study may lead to a huge public health problem, since Ivermectin is a medication that is not FDA approved for COVID treatment, and currently has proven to be ineffective in clinical trials, which are truly the gold standard to evaluate the efficacy of a medication.

Because of Elsevier’s frequent practice of overwriting original abstract pages with retractions without adding new dates, it is unclear when the paper was retracted, although it appears to have happened sometime this week.

By our count, researchers have retracted at least a dozen studies (including the latest one) on the use of ivermectin to treat Covid-19.

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5 thoughts on “Widely touted abstract on ivermectin and COVID-19 retracted”

  1. You can’t close Pandora’s box.

    Moreover, genuine question: is it a good idea to retract a paper not on the grounds of incorrect information or ethical issues, but because other people, fueled by politics, misinterpreted it?

    1. In cases like this, where the paper does not add materially to our knowledge do to the clear limitations of the study, the answer is unambiguously “yes”.

      It’s not a matter of suppression, but rather, of communication. Which is, after all, the point of a paper. Note that they chose not to submit it for publication for much the same reason.

      I might argue even when there is a material contribution, that retraction and publication of a revised version to mitigate misinterpretation, could be warranted.

      I see this as science, and scientists, taking ethical responsibility for their work and communication.

    2. Some clarifications: (1) This isn’t a paper, it’s an abstract; (2) It does in fact contain misleading information . Saying it’s being retracted to avoid “misinterpretation” is a bit of a euphemism that allows the authors to make a graceful exit rather than saying “our study was garbage.” But really it never should have been published in the first place, since the blatantly confounded design makes the results basically meaningless.

      1. Exactly! Using the above baseline for what should and should not proceed to publication just wiped out the vast majority of covid related publications.

  2. Unfortunately this type of study is commonly used as scientific evidence. Look nearly all of the observational epidemiological studies our nutrition guidelines are based on. The problem is when people are lied to and misled by their leader and experts and they see doctors unable to abide by their Hippocratic oath due to jobs and licenses being threatened for first doing no harm people don’t trust that retractions like this aren’t due to extreme pressure from government and/or pharmacy.

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